Creating Extensive Shift
Tables
OR
How I Learned to Type
1,388,571 wpm!
Kelley Weston
The goal:
Create a format that would consist of all the
possible combinations of several values.
For example:
"M1TM" - "M1TM" = "Missing to 1+ to Trace to Missing"
The usual way of accomplishing
this:
Typing all the combinations into a format.
When there are only 4 or 5 possible values
in 2 positions, this is no problem.
The problem:
We are starting with 7 values, in each of 4
positions. This results in 7 * 7 * 7 * 7 =
2401 combinations. The problems include:
time
ensuring that all possible combinations are
accounted for, with no repetitions or
omissions
accuracy
What I need to create:
value $CAT_ALL
"----"
"---1"
"---2"
"---M"
"---N"
"---O"
"---T"
"--1-"
"--11"
"--12"
"--1M"
"--1N"
"--1O"
"--1T"
"--2-"
"--21"
"--22"
"--2M"
"--2N"
"--2O"
"--2T"
"--M-"
"--M1"
"--M2"
"--MM"
"--MN"
"--MO"
"--MT"
"--N-"
"--N1"
"--N2"
"--NM"
(default = 40 fuzz = 0 min = 1 max = 40 )
- "----" = “missing"
- "---1" = "to 1+"
- "---2" = "to 2+"
- "---M" = "to Missing"
- "---N" = "to None"
- "---O" = "to Other"
- "---T" = "to Trace"
- "--1-" = "- to 1+"
- "--11" = "- to 1+ to 1+"
- "--12" = "- to 1+ to 2+"
- "--1M" = "- to 1+ to Missing"
- "--1N" = "- to 1+ to None"
- "--1O" = "- to 1+ to Other"
- "--1T" = "- to 1+ to Trace"
- "--2-" = "- to 2+"
- "--21" = "- to 2+ to 1+"
- "--22" = "- to 2+ to 2+"
- "--2M" = "- to 2+ to Missing"
- "--2N" = "- to 2+ to None"
- "--2O" = "- to 2+ to Other"
- "--2T" = "- to 2+ to Trace"
- "--M-" = "- to Missing"
- "--M1" = "- to Missing to 1+"
- "--M2" = "- to Missing to 2+"
- "--MM" = "- to Missing to Missing"
- "--MN" = "- to Missing to None"
- "--MO" = "- to Missing to Other"
- "--MT" = "- to Missing to Trace"
- "--N-" = "- to None"
- "--N1" = "- to None to 1+"
- "--N2" = "- to None to 2+"
- "--NM" = "- to None to Missing"
The solution:
Lots of Pepsi ®!
The Real Solution:
Let SAS® create the combinations AND the
meanings for them.
The method:
1.
2.
3.
4.
5.
Create a data set with the individual values and
meanings. This will only consist of a very few records.
In our case, we had 7 values.
Let SAS create all the combinations and put them into
a data set. We will cross the dataset with itself 3 times
to create the 4 positions. Remember the Cartesian
product?
Post-process the dataset to account for baseline and
missing values.
Create the datasets from which we will create the
permanent formats.
Write out the permanent formats.
Step 1 step 2a step 2b step 2c step 3
step 4a step 4b
step 5
Step 1
data work.temp;
length x $1
y $7;
x = 'T'; y =
x = '1'; y =
x = '2'; y =
x = 'O'; y =
x = 'M'; y =
x = '-'; y =
x = 'N'; y =
run;
'Trace';
'1+';
'2+';
'Other';
'Missing';
'-';
'None';
output;
output;
output;
output;
output;
output;
output;
outline
Step 2a
proc sql;
create table work.temp as
select x, y from work.temp
order by x;
outline
Step 2b
create table work.temp2 as
select (a.x !! b.x)
as x,
(a.y !! ' to ' !! b.y) as y
from work.temp as a,
work.temp as b;
outline
Step 2c
create table work.temp3 as
select (a.x !! b.x)
as x length = 200,
compbl(a.y !! ' to ' !! b.y)
as y length = 200
from work.temp2 as a,
work.temp2 as b;
outline
Step 3
data work.temp3 (drop = to_);
set work.temp3;
%* format these especially for baseline records;
if substr(x, 2) EQ '---'
then y = scan(y, 1) !! " at baseline";
%* eliminate "to -";
do while (index(y, "to -") GT 0);
to_ = index(y, "to -") ;
y
= left(trim(substr(y, 1, (to_ - 1)) !!
substr(y, (to_ + 4))));
end;
y = compbl(y);
run;
outline
Step 4a
data work.ctrl;
length x y $200;
length fmtname end $200;
set work.temp
end = last;
retain fmtname 'cat' type 'c';
rename x = start
y = label;
end = x;
run;
outline
Step 4b
data work.ctrl2;
length x y $200;
length fmtname end $200;
set work.temp3
end = last;
retain fmtname 'cat_all' type 'c';
rename x = start
y = label;
end = x;
run;
outline
Step 5
proc format library = library cntlin = work.ctrl;
run;
proc format library = library cntlin = work.ctrl2;
run;
outline
Conclusion
And that’s how I learned to
type 1,388,571 wpm !
And boy, am I tired !